42 ENDOSPORECE. [pHYSARUM.spores with rather few ovoid brown Ume-knots, or a looser net¬work of hyaUne threads, with numerous elongated irregularlybranching lime-knots. Spores pale brownish-violet, nearlysmooth, 8 to 10 /A diam.—P. Braunianum List, m Journ. Bot.1891, p. 259 (non de Bary).- Plate VIL, B.—a. sporangia, x 20; b. plasmodiooarp, x 20; u. capillitiumand spores, x 280 ; d. spore, x 600 (United States). This species is closely allied to P. globuliferum, from which thestalked form scarcely differs except in the brown colour of the limein the capiUitium and sporangium-wall. The specimen from Moffat,described in Journ. Bot., 1891, under the name P. Braunianum deBary, agrees with de Bary's description of that species in the usuallysessile form and brown lime-knots of the capillitium, but as the typeconsists of only a single gathering by A. Braun near Berlin, and is notrepresented in the Strassburg or British collections, no proof of identityhas been obtained ; the Moffat specimen is therefore placed underP. 7nurinum, the sessUe American forms of which it closely resembles. Hab. On dead leaves, wood, etc.—Moffat (L:B.M.14) ; Philadelphia ;(L:B.M.14) ; Ohio (L:B.M.14). 5. P. pulcherrimum Berk. & Rav., in Grev., ii., p. 65 (1873).Total height 1 mm. Sporangia globose, flattened beneath,stipitate, erect or inclined, purple, 0'4 to 0'5 mm. diam., gre¬garious. Sporangium-waU membranous, pale purple, withscattered clusters of large purple globular lime granules (1 /a diam.)Stalk purple, subulate, brittle, containing lime. Columella small,convex, or none. Capillitium a close network of delicate purplishthreads, broader and more expanded at the axils below; Ume-knots numerous, small, roundish, filled with purple globular lime-granules. Spores pale dull red, almost smooth, 7 to 8 /a diam.—Rost. Mon., p. 106, fig. 84; Mass., Mon., p. 293. Physarumatroruhrum Peck, in Rep. New York Mus., xxxi., p. 40; Mass.,Mon., p. 294. Plate VIIL, A.—a. sporangia, x 20 ; J. capillitium with fragment ofsporangium-wall and spores, x 280 ; c. spore, x 600 (United States). P. atrorubrum Peck is the same species (teste Dr. G. A. Rex). Hab. On dead wood.—Ohio (L:B.M.15) ; PhUadelphia (L:B.M.15) ;Iowa (B.M. 1013) ; S. Carolina (B. M. 412, 869). - * 6. P. citrinum Schumacher, Enum. PI. SadUi., U., p. 201 (1803).Plasmodium ? Total height 0'8 to 2 mm. Sporangia globose, rugose,stipitate, rarely nearly sessile, erect, yeUow to yellowish grey,0-4 to 0-7 mm. diam.; sporangium--wall membranous with innateclusters of yellow lime granules. Stalk golden yellow, opaquewith dense deposits of Ume, stout, somewhat furrowed, varying inlength, chalky in section, often rising from a vein-like hypo¬thaUus. Columella short, conical, or obtuse. CapiUitium asomewhat close network of hyaUne rigid threads -with flat ex¬pansions at the axUs, persistent after the dispersion of thespores; lime-knots yellow, numerous, varying in shape and size, usually rounded, seldom developed at the axUs of the branches.